G. Thomson. — On some Naturalized Plants of Otago. 371 



between Messrs. Travers and Kirk. For the future the evil may be to a great 

 extent avoided, by cataloguing all the non-indigenous plants hitherto collected, 

 and constantly supplementing this record by the addition of every fresh 

 discovery. It is quite unnecessary to point to the uncertainty which exists 

 with regard to a large proportion of the British flora as to its origin. In 

 this country there are some plants to which doubt may yet attach, as to the 

 time of their introduction and the place from which they were originally 

 carried. 



Perhaps there is no method by which foreign plants are introduced in 

 such quantity and variety as by the direct importation of agricultural and 

 other seeds from Britain and other countries where there is much cultivated 

 land. Every one conversant with rural matters in England or on the 

 Continent, knows that, even where high cultivation is the rule, hundreds of 

 species of weeds contest for possession of the soil, along with the legitimate 

 crop of the husbandman. The meadows and pastures teem with their own 

 peculiar weeds, and the seeds of these are certain to be present in greater or 

 less quantity in all grass seeds collected. English seedsmen are in the habit 

 also of purchasing largely from foreign importers, particularly heavy seeds, as 

 clovers, timothy, rape, etc., so that seed brought to this country from any 

 part of Britain is nearly sure to contain a great deal that is not bargained for, 

 even when most carefully selected. By this means also, the weeds of Europe, 

 America, India, etc., are distributed far and wide over our Colonial Empire, 

 and, as is too often the case, to the serious detriment of the country which 

 imports them. As a case in point, I may mention that, in 1869, a farmer 

 in Southland imported from Messrs. Lawson and Sons of London and 

 Edinburgh — a firm which has made the cultivation of grasses their speciality — 

 a quantity of selected grass seed for laying down in permanent pasture. The 

 assortment comprised twenty-one species of plants, but besides all that were 

 included in the list making their appearance in due- time, no less than thirty- 

 seven species of weeds were found among them, including the clover-dodder 

 {Guscuta trifolii), and other comparatively rare plants. 



In the Transactions of the N.Z. Institute, vol. 11., p. 131, Mr. Kirk 

 has drawn up a very elaborate series of divisions for the proper classification 

 of naturalized plants. One of the most rapid agencies for the diffusion 

 of such plants, and which affects horticultural as well as agricultural and 

 accidentally introduced species, is that of floods. The Taieri plain furnishes 

 a good example of this, plants from most diverse localities and introduced by 

 totally different agencies, being there found in close proximity to each other. 



In the accompanying list, I have to some extent followed the plan adopted 

 by Mr. Kirk, using two or three similar contractions, and dividing them into 

 similar series according to their method of introduction, viz : — ' 



